Tread link



April 12, 1932 A. P. ARMINGTON ET AL, 1,854,013

TREAD LINK Filed OCL. 27, 1931 2 Sheets-Sheet' l -mf /z ATTORNEYS Aprill2, 1932. A. HARMINGTON E'r AL f 1,854,013

TREAD LINK Filed Oct. 27, k1931 2 Sheets-'Sheet 2 Patented Apr. 12, 1932srATEs PATENT ori-cs ARTHUR P. ARMINGTON AND STEWART F. ARMINGTON, FWvILLOUGI-IBY, AND GEORGE E. ARMINGTON, OF SOUTH EUCLID, OHIO,lASSIGNORS T0 THE EUCLID ROAD MA- CHINERY COMPANY, OF E'CLID, OHIO, ACORPORATION OF OHIO Y TREAD LINK Application led October 27, 1931,.Serial No. 571,378.

This invention relates to links for endless tread linkages of the typeadapted to functionA as beams in their ground-engaging stretches. Alinkage capable of so functiont? ing is disclosed in'Patent No. 425,600,issued April 15, 1890, toEdwards, and its -manner of use is disclosed inPatent No. 1,458,962, issued June 19, 1923, to Athey.

' An analysis of the structure of the Athey linkage shows thateach linkvcomprises essentially a shoe element having hinge means at its ends andan upstanding bracketportion and tension elementsV pivotally supportedon the bracket portion. And, in a groundengaging stretch of the linkagethe shoe elements are stressed in compression, the tension elements arestressed -in tension, and are supported in spaced relation above theshoeelement-s to complete a beam inflexible upwardly. It will be noticedthatthere are a large number of these tension elements`,"two for each link,andy that stresses are transferred from one to another of them throughthe pins by which they are connected, so that lost motion due to wear atany of'these points `is cumulative throughout the stretch.v

Another type of link capable of so functioning in a linkage'is shown inPatentV No. 1,808,446, issued June 2, 1931, to Arthur P. Armington. 1 Y

This linkr is one, in which thebeam characteristic is imparted'bytruss-forming members rigidly associated' lwith their shoe elements, andacting as levers, each truss-'forming element of one shoehaving a faceadapted to abut a corresponding face rof the next adjacent Vshoe toprevent upward' flexing of the stretch. This type has the advantage ofsimplicity over the Athey type, butin operation has been found to wearrapidly at the 'faces of' the truss-forming members fdue to slidingmotion between abutting faces .in the ground-engaging stretch, whichmotion takes place as the links progress through the Zone of maximumstress, Vintermediate the f ends of the stretch. Y f

Generally the objects of this invention are improvements upon these twotypes of links, and in a sense to attain the advantages of both, withoutthe disadvantages of either. Y

and

Briefly we accomplish this by providing links each having a shoe elementconnected with those of its adjacent links, each having a tensionelement cooperative directly with those of both its adjacent links, eachshoe element having an upstanding bracket portion means movablysupporting its tension element thereupon, whereby in a stretch of saidlinkagethe shoe members of the links may act in compression, the tensionelements ymay coact as a separate tension member, and

the bracket portions of the links will locate t-he elements of saidtension member to complete a beam, the tension elements of which arefree to-assume straightened' relation inA the directions of theirstresses. Thus, all of the parts of each tension element are rigidlyassociated, as integral, and in a linkage thetension element of one linkdirectly engages those of the two adjacent links to providev a tensioncoupling therebetween.

The exact nature of this invention together with further vobjects andadvantages thereof i will be apparent from the following description,taken in connection with the`-accompanying drawings, illustrating partsas in "ground-engaging position and in VwhichFigs. 1, 2 and 3 are plan,and end andl side elevations respectively of a link embodyingourinvention, broken' lines in 3 indicating the manner of engagement of thetension element in a linkage; Figs. 4 and 5 ar-ejseparate :details ,ofthe two principal members of the link shown in Figs. 1 3, as in theplane of lines 4 5, Figs. land 2; Figs. 6, 7 and 8 are plan, end andside elevations respectively of another form of link embodying ourinvention, F ig. 8 including broken lines to indicaterthe manner ofcooperation of the tension elements in a linkage,'and Figs. 9 and 10 areseparate details of the two principal members of the link shown in Figs.6 7, as in ther-plane of lines 9, 10, Figs. 6 and 7.

VTiNith reference now to the embodimenty illustrated in Figs. 1-5inclusive, the principal members of the link are a tension element 1vsupported upon a base member 2 by a lpivotal connection provided by thepin 3.

vr'The lower portion of the base member 2 compris-es a flat shoe elementf4 which may li t) be generally hollow indicated, having a lowerground-engaging surface 5, thereabove a pair of rail surfaces 6, andhinge means at its ends in the form of staggered lugs 7 having thehinge-pin-receiving openings 8.

rlhe base member has one or more bracket' portions 9 upstanding from theshoe element and carrying the pin 3 transversely extending in elevatedposition. The bracket portions 9 include shelf portions 10 for a purposeto be described.

The tension element 1 has a through opening 11 by Which it is mountedupon the pin 3 between the bracket portions 9 of the base member. rl"hetension element comprises a pair of hook means 12, 13, rigidly relatedand with their bends in opposite directions as shown Figs. 3 and et.These hook means are preferably flat-faced as at 12 and 13 for engagingcorresponding parts of similailinks with ample bearing surface. Thetension element also has a face 151- overhanging the shelf of the memberto limit the motion of the tension member upon the pin 3 in onedirection.

In operation an endless linkage is made up of a plurality7 of such linksassembled together by hinge pins in the openings 8 Vin th-e usualmanner. The linkage is preferably mounted to travel from left to right,Fig. 3, in which case it Will be noted that the supporting axi 3 of thetension element is so located that in the ground-engaging stretch ofsaid linkage the faced portion 13 of the hook means 13 Will be ahead of,and the faced portion 12 of the hook means 12 Will be behind, the axis.The tension element is engaged by those of the next adjacent links asindicated in broken lines Fig. 3.

With reference now to the embodiment of Figs. @-10 inclusive. theprincipal members Aof' this link are a tension element 1a support-V edon a base member 2a by a pivotal connection provided by the pin 3.

As in the first embodiment, the lower portion of the base member 2a,comprises a ll'at shoe element la Which may be generally hollow asindicated, having a lovver groundengaging surface 5a, thereabove apairof rail surfaces 6a, `and hinge means at its ends in the form ofstaggered lugs 7a. having the hinge-pin-receiving openings 8a.

i The base member has one or more bracket portions 9a, upstanding fromthe shoe element and carrying the pin 3 transversely eX- tending inelevated position. The bracket portions 9a include shelf portions 10a.

The tension element 1a has a through openine- 11a by Which it is mountedupon the pin 3 between the bracket portions 9a of the base member. Thetension element comprises hook and eye portions and 21 respectively, solocated that the pin-receiving opening 11a. is beyond one of theseportions With respect to the other, in the example illustrated beingbeyond the eye portion 21 With respect to the hook portion 20. It Willbe apparent that both of these latter portions comprise essentially hookmeans, and they are preferably .flat-faced as at 20 and 21 for engagingcorresponding parts of similar links With ample bearing surface. Thetension element also has a face 14a overhanging the shelf 10a of thebase member to limit the motion of the tension member upon the pin 3 inone direction.

In operation, as before, an endless link- 4age is made up of a pluralityof such links assembled together by hinge pins in the openings' 8a inthe usual manner. The linkage is preferably mounted to travel from leftto right Fig. 8, in Which case it will be noted that the supporting aXis3 of the tension element 1a is ybehind the faced portions 20 and 21 ofthe latter. In the linkage, the 'hook portion 2O of a following linkWill engage in the eye Vportion 21 of its next adjacent leading link,with the faces 20 and 21 of the two parts in abutting relation, asindicated in broken lines Fig. 8.

It Will be noted that with both forms of links disclosed herein, thetension elements engage each other directly, as in a chain, to form bythemselves alone, a complete tension member, none of the tensionstresses along this member being carried by the pins 3. The duty of thelatter is therefore merely to position the tension elements in spacedrelation above the shoe elements. The load upon the pins 3 isconsequently light, there is practically no motion thereabout, andalthough it follows that 'there Will be 'substantially no Wear at thepins, still such Wear as may take place Will be immaterial 'so far asconcerns functioning of the parts. In any event the tension members arefree to adjust themselves along the lines of their stresses, so thatthere is no sliding bearing at Atheir faced portions. Consequently theselatter do not Wear, and the capacity of the linkage to function instretches Without upward -flexure, remains unimpaired.

Vhat We claim is:

1. In a tread linkage of the class described. a plurality of links, eachhaving a shoe element connected With those of its adjacent links, eachhaving a tension element cooperative directly with those of both itsadjacent links, each shoe element having an upstanding bracket portionand means movably supporting its tension element thereupon, whereby in astretch of said linkage the shoe members of the links may act incompression, the tension elements may coact as a complete tensionmember.y and the bracket portions of the links Will locate the elementsof said tension member to complete a beam, the tension elements of whichare free to assume straightened relation in the directions of theirstresses.

2. A tread link of the class described comprising a shoe element havinghinge means at its ends and an upstanding bracket portion, a tensionelement comprising a pair of hook means rigidly related with their bendsin opposite directions, said tension element having pivotal connectionwith said bracket portion, and being adapted to cooperate with thetension elements of adjacent similar links in a linkage to provide atension coupling therebetween.

8. A tread link of the class described com-` its ends and an upstandingbracket portion,

vand a tension element pivotally supported upon said bracket portion andhaving a pair of rigidly associated faced portions adapted to cooperatewith corresponding portions of adjacent similar links in a linkage toprovide a tension coupling therebetween, the supporting aXis of saidtension element being beyond one of said faced portions with respect tothe other faced portion thereof. l

5. A tread link of the class described comprising a shoe element havinghinge means at its ends and an upstanding bracket portion, and a tensionelement pivotally supported upon said bracket portion and having a pairof rigidly associated faced portions adapted to cooperate withcorresponding portions of adj acentsimilar links in a linkage to providea tension coupling therebetween, the supporting axis of said tensionelement being so located that in said linkage one of said faced portionsof said elements will be ahead, and the other behind said axis.

6. In a tread linkage of the class described, a plurality of links, eachhaving a shoe element connected with those of its adjacent links, eachhaving a rigid tension element cooperative directly with those of bothits adjacent links, each shoe element having an upstanding bracketportion and means movably supporting its tension element thereupon,whereby in a stretch ofsaid linkage the shoe members kof the links mayact in compression, the tension elements may coact as a complete tensionmember, and the bracket portions of the links will locate the elementsof said tension member to completea beam, the tension elements of whichare free to assume straightened relation in the directions of theirstresses. y V

7. A tread link of the class described comprising a shoe element havinghinge means at its ends and a rigidly upstanding bracket portion, and atension element pivotally supported upon said bracket portion and havinga pair of face portions adapted to bear directlyagainst correspondingportions of the tension elements of adjacent similar links in a linkageto provide a tension coupling therebetween.

8. A tread link of the class described comprising a shoe Velement havinghinge means at its ends and an upstanding bracket portion, and a tensionelement pivotally supported upon said bracket portion and having a pairof rigidly interassociated faced portions adapted to cooperate withcorresponding portions of adjacent similar links in a linkage to providea tension coupling therebetween.

In testimony whereof We hereby aiX our signatures.

ARTHUR P. ARMINGTON. STEWART F. ARMINGTON. GEORGE E. ARMINGTON.

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